Ordered and Reprocessable Smectic Liquid Crystal Elastomers via Bulk Thiol–Ene Polymerization

This research introduces a solvent-free thermal thiol–ene polymerization strategy using an allyl-functionalized twin-mesogen monomer and multifunctional thiols to fabricate smectic liquid crystal elastomers (LCEs). Upon polymerization, a transition from a nematic monomer state to a highly ordered smectic elastomer network is induced. The resulting LCEs exhibit well-defined liquid crystalline order, robust mechanical properties, and thermally activated stress relaxation, enabling reprocessing while preserving smectic order. The LCEs also show stable thermally triggered shape-memory behavior over multiple cycles. In addition, both pristine and reprocessed polymers exhibit enhanced thermal conductivity (~0.4 W m^-1 K^-1), nearly twice that of conventional thermosets. These results demonstrate an efficient route to ordered and reprocessable liquid crystalline networks via bulk thiol–ene polymerization.